1. Field of the Invention
The invention relates to a rotary electric machine stator and a method of manufacturing such a stator.
2. Description of the Related Art
A stator coil that is formed of a plurality of conductor segments that is disposed in slots of a stator and welded to one another has been proposed. For example, Japanese Patent 3196738 discloses a stator coil formed of a plurality of conductor segments that is welded to one another.
In such a stator coil, a pair of straight portions of a U-shaped conductor segment is inserted into a pair of slots that is one pole-pitch spaced apart from each other and the ends of the straight portions are welded to others. The Japanese patent proposes a twister to bend portions of ends of a pair of straight portions portions of U-shaped conductor segments that extends in the axial direction from an end of a stator core to be welded and a lifting driver to move the ends in an axial direction. That is, manufacturing work of the stator coil formed of a plurality of U-shaped conductor segments includes a step of bending ends of the conductor segments and a step of welding the ends to others. However, the step of bending is rather complicated.
JP-A-2001-37131 discloses stator having a plurality of L-shaped conductor segments that are inserted in slots of a stator and are welded to one another at opposite ends thereof. Although the stator does not require a step of bending, the stator has twice as many welding portions and portions to insulate as a stator having U-shaped conductor segments.